Snot good. In fact, it's terrible.

While hiking along the Esopus river in Shandaken, I spied this sign nailed to a tree. At first, I felt my heart sink, thinking it was a "Missing Child" poster. On closer inspection, it was my stomach that had a bad reaction.

What is that poor girl covered in - Slime? Cooties? Boogers? Um, kinda sorta. It's the aptly named Rock Snot, aka Didymosphenia geminata or just plain Didymo for you rappers out there. It's a fast-spreading algae found in streams and rivers all over the world. It grows in long gooey masses that resemble big honkin' wads of snot. Scientists are confounded by its recent aggressiveness and are unsure whether environmental changes or genetic mutations are to blame.

Unlike the Blob, freezing won't kill it. There are no known ways to eradicate the tenacious Snot, which can survive for 90 days on the sole of a boot, making it easy for anglers to transport it from river to river. Preventing its spread* is one way to control it, hence the signage. More gross-out facts about Rock Snot can be found here. I'm going to wash my boots now.

*In New Zealand, if you knowingly transport Rock Snot from one stream to another, you may be looking at 5 years in the clink!